Defining Outcome Measures for Psoriatic Arthritis: A Report from the GRAPPA-OMERACT Working Group.

The Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA)-Outcome Measures in Rheumatology (OMERACT) Psoriatic Arthritis (PsA) Core Set working group recently published the updated 2016 psoriatic arthritis (PsA) core domain set, a set of disease features that should be measured in all clinical trials. At the GRAPPA annual meeting in July 2016, the PsA working group presented the updated PsA core domain set endorsed by 90% of participants at OMERACT in May 2016 and drafted a roadmap for the development of the PsA core outcome measurement set. In this manuscript, we review the development process of the PsA core domain set and the ongoing and proposed work streams for development of a PsA core measurement set.